One of the most coolest advantages of Joomla is the extensible ability; you know, with 9000+ extensions on Joomla Extensions Directory (JED).

However, if you are new to Joomla & get confused with what extensions are necessary for your website, take a look at the inforgraphic about 9 must-have Joomla 2.5 extensions below. Thanks to them, you can use Joomla more easily and more securely. You can also do SEO on your website better.